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Raygun Extruder

Just a quick update. I finished reassembling the extruder last week. Compared to the old raygun, the new one has a few notable changes. The heat sink's closer to the heater block, to try and reduce the coefficient of friction between the walls and molten plastic. The leads of the resistor and the thermistor are insulated within concrete, so they won't short to the heater block. The cooling fan's fastened on better. Most notably, the hot end of the hot end is now swaddled in fiberglass - bona fide insulation.

On the bright side, the hot end performs like a champ. Only the lower two washers of the heat sink were warm, and the heater block came up to temperature with much more authority than usual.

Unfortunately, it still doesn't work. I tried an extrusion yesterday, to no avail. The printer produced a few sickly-looking brown blobs of plastic (my filament's white), but refused to extrude filament.

I decided that I needed to build a new extruder that would stay cold at the top. As long as I was rebuilding, I decided to do away with the metal-plastic interface, a common failure point. I found a design online that used a metal heat sink to replace the plastic thermal barrier, and have been building it for the past week.

The first step was visiting the hardware store. They had most of what I needed, mixed between metric and Imperial units (ugh). I bought a few 6x110 mm threaded rods for the central barrel, a pair of 4x50mm bolts for anchoring the hot end, a 2" fender washer for anchoring, and half a dozen 1½" fender washers for the heat sink.